This invention relates generally to the art of devices for preventing the spread of fire through plumbing pipes of buildings, and more particularly, to the art of fire-stop collars for surrounding pipes at wall barriers.
For a number of years, pipe networks which have extended through floors of buildings have been made fire retardant by encircling individual pipes with fire-stop intumescent material which expands upon contact with heat to close off pipe openings in the floors. It has been suggested to encircle such an intumescent collar with a container formed of a metallic band and then to attach the metallic container to a bottom surface of a floor through which the pipe passes. However, difficulties in accomplishing this have been encountered with prior-art arrangements because the intumescent material must often be installed at a different time from the pipe, sometimes being put in place after the pipe has been extended through holes in floors. The main difficulty in carrying out such a procedure is that prior-art fire-stop intumescent material collars have had to be formed at job sites, which has been inconvenient and time consuming for workman. It is therefore an object of this invention to provide a method for constructing a fire-stop collar assembly, at a factory which can be mounted on a pipe string at a separate installation site after the pipe has been assembled.
A suggestion has been made for producing a fire-stop pipe coupling adaptor at a factory which includes a pipe coupling having a fire-stop collar and metallic band wrapped thereabout. This fire-stop pipe coupling adaptor is to be used with a coupler which is cast into a wall barrier of a building. After a concrete wall barrier has cured with a cast-in coupler molded therein a male coupling member of the pipe coupling of the adaptor is inserted into one end of the cast-in coupling and radial tabs of the metallic band of the adaptor are then attached to the concrete wall barrier so as to hold the adaptor against the barrier at the cast-in coupling. A further pipe is then mounted to an outside end of the pipe coupling of the fire-stop pipe coupling adaptor. This fire-stop pipe coupling adaptor has many advantages, however, it does have some disadvantage. One disadvantage is that it requires additional work by a plumber, first attaching the adaptor to the cast-in coupling and then attaching a pipe to the adaptor. Also, such a fire-stop pipe coupling adaptor is not sufficiently flexible in use in that it can only be installed before a pipe string has been attached to a cast-in coupling. In this regard, sometimes it is desireable for a plumber to install a pipe string and then later install an intumescent collar. Thus, it is an object of this invention, to provide a method for constructing a fire-stop collar assembly which does not require an undue amount of work by a plumber to install and which can be installed either before or after a pipe string has been attached to a cast-in coupling.
Yet another difficulty with the prior-art fire-stop pipe coupling adaptor described above is that it comprises a special pipe coupling and is thereby somewhat expensive to produce. Thus, it is an object of this invention to provide a method for constructing a pipe-stop collar assembly which can be used with standard pipe.
It is a further object of this invention, to provide a method of constructing a fire-stop collar assembly which is relatively easy and relatively inexpensive to carry out and which thereby produces relatively inexpensive fire-stop collar assemblies.
It is a further object of this invention to provide a fire-stop collar assembly which is extremely easy to install and which can be installed quickly by normally trained plumbers.